Skirmish in the Campagna district

The Skirmish in the Campagna district (August 1503) was a battle of the Italian Wars that occurred when a force of Venetian mercenaries, disguised as French Army soldiers, surprised the French noble Octavian de Valois and his troops at their encampment in the Castra Praetoria, slaying the Baron and driving the French from Rome. The battle deprived the Borgia of the support of their French allies.

Background
In 1500, Cesare de Borgia convinced King Louis XII of France to loan him an army for his campaigns in the Romagna, and the French king sent his cousin, Baron Octavian de Valois, with an army to help the Papal States. The Venetian condottiero Bartolomeo d'Alviano had enemies to fight on both sides: the French to the north and the Borgia to the south. His men held their own, but the war was not going well, as he could not keep up with the pressure. Eventually, Ezio Auditore da Firenze's attacks on the Borgia towers in Rome and his assassinations of key Borgia lieutenants weakened the Papal forces, and d'Alviano sought to counterattack against the French. He repelled a French assault on his encampment, with Ezio Auditore closing the gates and fighting off the French troops trapped within the walls of the mercenary camp. The Baron de Valois then arrived, and he announced that he had captured d'Alviano's wife, Pantasilea Baglioni; he threatened to kill her, unless d'Alviano surrendered to him. Auditore hatched a brilliant plan to defeat the French: the Venetian troops could ambush and assassinate several French guards and steal their uniforms, and they could bring d'Alviano to the French general in chains. Auditore killed 20 French soldiers and stole their uniforms, and he wore the uniform of a captain. The mercenaries, dressed in French uniforms, accompanied him as he marched on the French encampment, and he dispatched any guards en route, preserving the secrecy of the operation.

Battle
When the mercenaries arrived at the gates, a French sentry demanded to know what part of France Auditore was from, hoping to ascertain that he was, indeed, a French officer. Auditore answered "Montreal", and the French sentries opened the gates. Auditore proceeded to enter the encampment with d'Alviano, and the mercenaries then turned on the French soldiers inside of the Castra Praetoria. Auditore travelled across rooftops to head towards the French general's headquarters as the mercenaries fought off the French soldiers. Valois held his pistol to Baglioni's head, threatening to shoot her if Auditore drew near, but Auditore stealthily entered the headquarters, assassinating the sentry on the rooftop entrance. He proceeded to jump onto a post and jump down, assassinating the Baron with his hidden blades. The Baron's death threw the French into disarray, and the French soldiers abandoned their encampments in Rome. Baglioni was reunited with her husband, who was overjoyed by this success. The skirmish ensured that the French presence in Rome was at an end, and it relieved much of the pressure put on the Venetian mercenaries during their fight against the Borgia. With Cesare's banker Juan Borgia and his French ally Valois dead, he was now targeted by Auditore, who now set out to drive the Borgia from Rome.